SHAFT AS-CENTER 7S6855 - Caterpillar

Lubricants
The engine, transmission and hydraulic oil viscosities have an effect on engine starting. The higher the viscosity and the colder the lubricant, the more starting load it puts on an engine. In general, the lubricant grades (with specific viscosity ranges) in the chart which follows are acceptable for the given ambient temperatures. Other lubricant grades with different temperature ranges and lubricants for colder temperature applications are given in the "Operation And Maintenance Guide, Cold Weather Operation," Form No. SEBU5338.
When the temperature is below -18°C (0°F), always remove the dipstick and check to see if the oil will flow down the dipstick. If the oil will not flow, DO NOT start the engine. If the engine is started, damage is probable. Remember, fresh, clean oil will flow at lower temperatures than dirty oil.
Batteries
The battery must have enough cranking capacity for the starter to turn the engine at 100 to 120 rpm. But, battery capacity decreases as the temperature of the electrolyte decreases.
This is because the electrochemical action in the electrolyte is slower. For example, a fully-charged battery has available only 40% of the cranking power at -18°C (0°F) that it has at 27°C (80°F). Also, the lubrication gets thicker in cold weather and adds to the starting load.
For these reasons, the battery must be fully charged at all times to have the cranking power capacity necessary to start the engine. The corrected specific gravity for a fully-charged battery is 1.260.
Starting Aids
At temperatures of 16°C (60°F) and below, the recommendation is to use glow plugs on engines so equipped. At temperatures between -12°C (10°F) and -23°C (-10°F) use the glow plugs and a coolant heater. The chart which follows gives the minimum times for glow plug operation.
Ether starting aids are to be used at ambient temperatures of 0°C (32°F) and below for direct injection engines. Ether is to be used at temperatures of -18°C (0°F) and below for engines with precombustion chambers.
Starting Information For 621 Tractors
Use the information which follows, along with the above information, when starting 621 Tractors.
For machines with Serial Numbers 23H1820-Up, make sure the air/fuel ratio control is not engaged when the engine is started.
For machines with Serial Numbers 23H1-Up which are equipped with manual transmissions, move the transmission control lever to any gear position except neutral. Make sure the clutch is not engaged. Start the engine.
If the machine is equipped with a semi-automatic transmission, move the transmission control lever to the reverse-, first- or second-gear position. Start the engine. After the engine is in operation, move the transmission control lever to the neutral position to activate the control valve. Then, the transmission control lever can be moved for a gear selection, and the machine will move.
Make a reference to this article in the Operation And Maintenance Guides for all tractor-scrapers.